Ramps are either easy or complicated to make and installed.
If you want a simple and functional ramp any plank of wood cut and sanded then install with double tape would do the job.
If you want to get fancy you’d need to then put radius on the ramp at the same radus or slighter flatter than your fingerboard. Making tabs to install the pickup screw on the jazz pickups can be tricky but not necessary.
Here are some of what I have installed on mine, as well as some that I printed.
